Blast actuated module valve

ABSTRACT

A closure device for installation in ventilation ducts of protective structures comprising a normally open valve plate mechanically connected to a piston which is blast actuated to pivot the valve plate to a closed position thus effectively sealing the device. A spring assembly maintains the valve plate in a sealed position once it is closed by the blast actuated piston.

G United States Patent 1 3,561,346

[72] Inventors .(lphn lviilstegilepson [56] Ref en Ci d aman o, l DonaldE. Williams, Santa Barbara, Calif. UNITE]? STATES PATENTS [2]] Appl No.802,525 3,139,811 7/1964 S1ckel 98/119 [22] Filed Feb'26 1969 3,412,75511/1968 Mason 98/119 Patented Feb. 9 ROSSN: Assignee the United Statesof America as represented 3,459,] 14 BaCllI'll 98/1 19 by h S c e y of ha y Primary Examiner-Meyer Perlin AltorneysEdgar J. Brower, Q. BaxterWarner and Gayward N. Mann ABSTRACT: A closure device for installationin ventilation [54] BLAST ACTUATED MODULE VALVE ducts of protectivestructures comprising a normallv open 5 Claims 5 Drawing Figs. valveplate mechanically connected to a piston vvhlch lS blast actuated topivot the valve plate to a closed position thus ef- [52] US. Cl 98/119fectively sealing the device. A spring assembly maintains the 1 'l F23113/00 valve plate in a sealed position once it is closed by the blastac- [50] Field of Search 98/1 19 mated iston.

PATENTEB FEB 9am SHEET 1 OF 3 INVENTORS JOHN MJSTEPHENSOI BY DONALDE.W|LL|AMS 2 W @w Z BAFM,, J9) ATTORNEYS PATENIEDFEB 9:97: 3,5 1 34 sum3 or 3 has fin w 1 I BLAST ACTUATED MODULE VALVE BACKGROUND OF THEINVENTION l Field of the Invention The present invention relates toclosure devices for installation in ventilation ducts and morespecifically the invention relates to ventilation closure devices whichare blast actuated.

2. Description of the Prior Art Numerous closure devices have beendeveloped for installation in ventilation ducts of personnel shelters toprotect against high pressures and shock forces from nuclear blasts.Such devices are activated either by the blast itself or by a mechanismtriggered through a sensing unit which responds to phenomena resultingfrom the nuclear explosion.

The disadvantage of sensor operated closure devices lies in thevulnerability of the sensors to damage and 'false alarms while theprimary disadvantages of existing blast operated closure devices includeexcessive bypassed overpressure when delay ducts are not employed andexcessively long delay ducts when they are used.

The effectiveness of any blast closure device is generally measured interms of its bypassed pressure pulse or more explicitly by the portionof a blast wave which is allowed to pass through the closure deviceduring the closure operation. There is no prior art device capable ofexcluding a bypassed pressure pulse but the problem is circumvented bythe use of delay ducts. The length of the delay duct then becomes ameasure of the efficiency of the closure device since the length of thedelay duct can be decreased with accompanying decreases in the closingtime of the device. With the present invention, however, a very rapidclosure time is effected providing for complete exclusion of the blastwave with only a very short delay duct. Moreover, if a slight bypassedpressure pulse can be tolerated the closure device may be directly blastactuated with complete absence of any delay duct thus providing for thefirst time a blast actuated closure apparatus in which delay ducts formno significant part thereof.

SUMMARY OF THE INVENTION The present concept is directed to a closuredevice for incorporation into ventilation ducts of protective sheltersto protect personnel and equipment therein from the effects of a nuclearblast. Moreover the present device maintains the air at atmosphericpressure during the negative pressure phase following any nuclear blastby remaining closed until such time as the device is required to bereopened.

Briefly the blast closure device of the present invention comprises ashort conical tube in which is operatively mounted a piston with amechanical linkage to a valve plate. Most of the blast wave which movesinto the ventilation duct, referred to hereinafter as the primaryportion, enters the conical tube and impinges on the piston which urgesthe valve plate to a closed position against a valve seat thus sealingthe shelter against either external high or low pressure air. A springassembly and cooperating pushrod assists in the closure of the valveplate once the blast has actuated movement thereof.

A delay duct is normally incorporated into the ventilation system and isadapted to receive that portion of the blast wave which did not enterthe conical tube and referred to for descriptive purposes as thesecondary portion of the shock wave. The delay duct is of such lengththat the secondary portion of the blast wave will not arrive at thepresent blast device until after it has been closed by the primaryportion of said blast wave in a manner described above. However, if aslight bypassed pressure pulse can be tolerated, the delay duct may becompletely omitted as part of the device.

STATEMENT OF THE OBJECTS OF INVENTION One object of the presentinvention, therefore, is to provide means for very rapid closure ofventilation ducts within protective shelters so as to protect thepersonnel and equipment therein against the effects of a nuclear blast.

A further object of the invention is to provide a blast operatedventilation duct valve which seals the duct to both high and lowpressure phases of a nuclear blast.

Another object of the invention is to provide a blast actuatedventilation duct valve having a relatively short delay duct incorporatedtherein.

An additional object of the invention is to provide a simple. economicaland reliable blast operated ventilation duct valve.

Other objects. advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective diagrammaticview partly broken away of a preferred embodiment of this invention.

FIG. 2 is a vertical sectional view of a device embodying the principlesof the present invention.

FIG. 3 is a horizontal sectional view along the line 3-3 of FIG. 2.

FIG. 4 is an enlarged vertical section through one spring assemblyshowing the structure in detail.

FIG. 5 is a diagrammatic view of a ventilation system incorporating thedevice of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The blast actuated valve of thepresent invention may readily be mounted in a modular relationshipwithin a ventilation duct either singly or in parallel banks. Withreference to FIGS. 1 to 3 a single valve assembly comprises a valvehousing 10 having end flanges 12, sidewalls 14, top plate 16 and bottomplate 18. A series of spaced parallel reinforcing ribs 20 are positionedabout the exterior of housing 10 and are attached to each of the endwalls 12, as well as to their adjacent or bottom plate 16 or 18.Similarly spaced parallel ribs 22 may extend transversely across theexterior of housing 10 at right angles to ribs 20 and be attached toeach sidewall 14 and also the adjacent top plate 16 or bottom plate 18.At their points of intersection ribs 20 and 22 may be secured to eachother.

A conical shaped duct or shock catcher 24 is mounted on the top plate 16by the boss 26 as shown in FIGS. 1 and 2 and is adapted to receive mostof the blast wave (i.e., the primary portion of a blast wave) within theouter expanded portion 28 thereof. The conical configuration of theshock catcher is designed to direct the full force of the blast wavecaptured within the expanded portion 28 into the throat section 30 whereit strikes a flat circular piston 32 movably positioned therein. I

Piston 32 is supported on the upper end of piston rod 34 which slides upand down within bushings 36 and 38. Both the piston 32 and piston rod 34are adapted for immediate response to the blast wave focused within theshock catcher 24.

A plate actuating cam 40 is operatively attached to the piston rod 34within housing 10 and transmits any movement thereof to a rectangularshaped valve plate 42 which is mounted within housing 10 and hingedlyconnected to a valve seat 44 along the rear edge 46. The valve plate 42is then adapted to move rapidly in a pivoting motion toward valve seat44 thus closing the valve and protecting the ventilation duct in whichit may be mounted against any harmful high pressure shock waves.

A series of valve plate reinforcement elements 48 are mounted on theupper surface of valve plate 42 in spaced relationship and areintegrally connected to a transverse shaft 51 mounted in the opposedsidewalls 14 of housing 10 thus holding the hinged edge of both valveplate 42 and of valve seat 44 in a suitable pivotal position.

Duringnormal operation the valve is open. In this respect valve plate 42is held in an open position by a pair of spaced parallel springassemblies 50 mounted within housing 10 in front of valve plate 42 andby a pair of cooperating pushrods 52 which are each operathelypositioned at one end relative to each spring assembly 50. while theopposite end is pivotally connected at 54 to the forward portion ofvalve plate 42 in a manner substantially as shown in the drawing.However as soon as the valve plate 42 is actuated. the spring assemblies50 and pushrods 52 will aid in the closure operation by snapping thevalve plate 42 against the valve seat 44.

Each spring assembly 50. shown best in PK]. 4, includes a stationarysupport tube 56. an elongated cam follower sleeve 58 slidably supportedtherein and a hollow spring encompassing quill 60 which telescopes intosleeve 58 when the spring 62 is compressed. As shown quill 60 has anenlarged head 63 which has a central depression 65 preferably conical inshape.

The closed end 67 of cam follower sleeve 58 is contiguous to springrelief cam 64 which in turn is mounted on cam shaft 66 transverselypositioned and rotatably supportd in opposed sidewalls 14.

The opposed end of quill 60 is adapted to receive the forward end ofpushrod 52 in the central depression 65 while the spring 68 positionedwithin the interior thereof serves through rod 52 to maintain constantpressure against the valve plate 42 thus in effect keeping the valveplate open, or when tripped by the blast wave, snapping it closed.

The spring assemblies 50 have several functions. They hold the valveplate 42 open during normal operation. They provide a significantclosure force component. When closure is effected. they maintain a sealbetween valve plate 42 and valve seat 44 and they prevent a prematureopening during the negative pressure phase following a nuclear blast.

To reopen a closed valve, shaft 66 is rotated with a suitable crank ortool applied over one of the squared ends 69. Spring relief earns 64 arethen rotated to the low point which allows cam followers 62 to ease thusremoving spring pressure from rods 62. Thereupon valve plate 42 may beopened from valve seat 44. When valve plate 42 has been pivoted to theopen position cam shaft 66 and spring relief cam 64 are again rotated tothe position which exerts compression pressure on spring 58 through camfollower 62 thus in effect cocking the valve for future use.

When the major or primary portion of any blast wave from an inlet duct68 enters the shock catcher 24, a minor or secondary portion of the samewave will enter a delay duct 70 as indicated in HO. 5. The length ofdelay duct 70 is predetermined so that the travel time of the secondaryportion of the blast wave which enters therein is greater than thetravel time of the primary portion which entered the shock catcher 24plus the time required to close valve plate 42. Thus it is seen that aseal is effected between the delay duct 70 and outlet duct 72 (FIG.prior to arrival at the sealed valve of the secondary portion of theblast wave from the delay duct. It is to be noted that due to the rapidclosure of the valve plate 42 against valve seat 44 only a very shortdelay duct 70 is necessary to completely exclude the blast wave.

As a result of the very rapid closure valve seat 42 against valve seat44. the use of a delay duct 68 may be completely avoided and the valvedirectly blast actuated provided a slight bypassed pressure pulse can betolerated.

If so desired the present valve may be easily amenable to sensoroperation. It should be kept in mind. however, that sensor devices arehighly vulnerable to explosion characteristics and false alarms.

If the valve seat 44 could be mounted with a solid foundation to whichthe other structure components could be attached. the valve housing 10and related structures could be eliminated. Moreover if lightweightflame resistant materials were used in manufacturing the variousstructural elements of the present valve, an even faster closure timemay be realized.

We claim:

1. Means for interrupting the flow of air through a duct when said flowincludes a blast wave of predetermined magnitude comprising:

a housing forming a part of the duct;

a valve seat located within said housing and having an opening throughwhich the ducted air must pass;

a valve plate movable from an open position away from said seat to aclosed position abutting said seat;

a force exerting means linked to said plate;

said linkage in a first position urging the plate open away from theseat and in a second position urging the plate closed against the saidseat;

control means separate from said valve plate acting upon the linkage toshift the plate from the first position to the second position; and

said control means being responsive to a blast wave included in the flowof ducted air.

2. The device of claim 1 wherein the force exerting means comprises aresilient spring and the linkage includes a toggle joint.

3. The device of claim 2 wherein the control means acts upon the togglejoint to move the linkage from its first position to its secondposition.

4. The device of claim 1 wherein means is provided to remove and restorethe force exerted by the force exerting means;

said means being operable from without said housing.

5. The device of claim 1 wherein the duct has an inlet and outlet andwherein a separate delay duct connects a portion of the inlet duct withthe valve housing;

said delay duct being of sufficient predetermined length to insure thatthe portion of shock wave entering therein does not reach the valvehousing until the valve plate is closed.

1. Means for interrupting the flow of air through a duct when said flowincludes a blast wave of predetermined magnitude comprising: a housingforming a part of the duct; a valve seat located within said housing andhaving an opening through which the ducted air must pass; a valve platemovable from an open position away from said seat to a closed positionabutting said seat; a force exerting means linked to said plate; saidlinkage in a first position urging the plate open away from the seat andin a second position urging the plate closed against the said seat;control means separate from said valve plate acting upon the linkage toshift the plate from the first position to the second position; and saidcontrol means being responsive to a blast wave included in the flow ofducted air.
 2. The device of claim 1 wherein the force exerting meanscomprises a resilient spring and the linkage includes a toggle joint. 3.The device of claim 2 wherein the control means acts upon the togglejoint to move the linkage from its first position to its secondposition.
 4. The device of claim 1 wherein means is provided to removeand restore the force exerted by the force exerting means; said meansbeing operable from without said housing.
 5. The device of claim 1wherein the duct has an inlet and outlet and wherein a separate delayduct connects a portion of the inlet duct with the valve housing; saiddelay duct being of sufficient predetermined length to insure that theportion of shock wave entering therein does not reach the valve housinguntil the valve plate is closed.